VIEW ARTICLE    DOI: 10.1094/ASBCJ-53-0136

Factors Influencing the Stability of Barley Malt beta-Glucanase During Mashing. Robert Muller, BRF International, Lyttel Hall, Nutfield, Surrey, U.K. RH1 4HY. J. Am. Soc. Brew. Chem. 53(3):136-140, 1995. Accepted March 20, 1995.

Barley malt beta-glucanase has a half-life of approximately 40 min at 45°C. Three experimental procedures increased the survival of this activity to 85% under the same conditions. Addition of sodium dithionite to the mash was effective, as was reducing the pH of the cold malt slurry (to pH 2.3 for 20 min) before returning to normal mash pH (5.6) prior to heat treatment. Separation of the beta-glucanase activity from other proteins also enhanced stability. Recombination of separated fractions indicated that the inhibitory factor had a relative molecular weight of about 66,000. This fraction did not have beta-glucanase activity but coincided with a peak of peroxidase activity that was lost during acid/base treatment. Keywords: beta-Glucanase, Mashing, Oxidation, Peroxidase, Stability